#ifndef __LOG_HPP__
#define __LOG_HPP__

#include <iostream>
#include <cstdio>
#include <string>
#include <sstream>
#include <fstream>
#include <memory>
#include <ctime>
#include <unistd.h>
#include <experimental/filesystem> // Header file for pre-standard implementation
#include "Mutex.hpp"

namespace LogModule
{
    using namespace MutexModule;
    const std::string gsep = "\r\n";
    class LogStrategy
    {
    public:
        ~LogStrategy() = default;
        virtual void SyncLog(const std::string &message) = 0;
    };

    class ConsoleLogStrategy : public LogStrategy
    {
    public:
        ConsoleLogStrategy()
        {

        }

        void SyncLog(const std::string &message)
        {
            LockGuard lockgurad(_mutex);
            std::cout << message << std::endl;
        }

        ~ConsoleLogStrategy()
        {

        }
    private:
        Mutex _mutex;
    };

    const std::string defaultpath = "./log";
    const std::string defaultfile = "my.log";

    class FileLogStrategy : public LogStrategy
    {
    public:
        FileLogStrategy(const std::string &path = defaultpath, const std::string &file = defaultfile)
            :_path(path),
            _file(file)
        {
            LockGuard lockgurad(_mutex);
            if(std::experimental::filesystem::exists(_path))
            {
                return;
            }
            try
            {
                std::experimental::filesystem::create_directories(_path);
            }
            catch(const std::experimental::filesystem::filesystem_error &e)
            {
                std::cerr << e.what() << '\n';
            }
            
        }

        void SyncLog(const std::string &message)
        {
            LockGuard lockgurad(_mutex);

            std::string filename = _path + (_path.back() == '/' ? "" : "/") + _file;
            std::ofstream out(filename, std::ios::app);
            if(!out.is_open())
            {
                return;
            }
            out << message << gsep;
            out.close();
        }

        ~FileLogStrategy()
        {}
    private:
        std::string _path;
        std::string _file;
        MutexModule::Mutex _mutex;
    };

    enum class LogLevel
    {
        DEBUG,
        INFO,
        WARNING,
        ERROR,
        FATAL
    };

    std::string LevelToStr(LogLevel level)
    {
        switch(level)
        {
            case LogLevel::DEBUG:
                return "DEBUG";
            case LogLevel::INFO:
                return "INFO";
            case LogLevel::WARNING:
                return "WARNING";
            case LogLevel::ERROR:
                return "ERROR";
            case LogLevel::FATAL:
                return "FATAL";
            default:
                return "UNKNOWN";
        }
    }

    std::string GetTimeStamp()
    {
        time_t curr = time(nullptr);
        struct tm curr_tm;
        localtime_r(&curr, &curr_tm);
        char timebuffer[128];
        snprintf(timebuffer, sizeof(timebuffer), "%4d-%02d-%02d %02d:%02d:%02d",
            curr_tm.tm_year + 1900,
            curr_tm.tm_mon + 1,
            curr_tm.tm_mday,
            curr_tm.tm_hour,
            curr_tm.tm_min,
            curr_tm.tm_sec
        );
        return timebuffer;
    }

    class Logger
    {
    public:
        Logger()
        {
            EnableConsoleLogStrategy();
        }

        void EnableFileLogStrategy()
        {
            _fflush_strategy = std::make_unique<FileLogStrategy>();
        }

        void EnableConsoleLogStrategy()
        {
            _fflush_strategy = std::make_unique<ConsoleLogStrategy>();
        }

        class LogMessage
        {
        public:
            LogMessage(LogLevel &level, std::string &src_name, int line_number, Logger &logger)
                :_curr_time(GetTimeStamp()),
                _level(level),
                _pid(getpid()),
                _src_name(src_name),
                _line_number(line_number),
                _logger(logger)
            {
                std::stringstream ss;
                ss << "[" << _curr_time << "] "
                   << "[" << LevelToStr(_level) << "] "
                   << "[" << _pid << "] "
                   << "[" << _src_name << "] "
                   << "[" << _line_number << "] "
                   << "- ";
                _loginfo = ss.str();
            }

            template<class T>
            LogMessage &operator<<(const T &info)
            {
                std::stringstream ss;
                ss << info;
                _loginfo += ss.str();
                return *this;
            }

            ~LogMessage()
            {
                if(_logger._fflush_strategy)
                {
                    _logger._fflush_strategy->SyncLog(_loginfo);
                }
            }
        private:
            std::string _curr_time;
            LogLevel _level;
            pid_t _pid;
            std::string _src_name;
            int _line_number;
            std::string _loginfo;
            Logger &_logger;
        };
        LogMessage operator()(LogLevel level, std::string name, int line)
        {
            return LogMessage(level, name, line, *this);
        }
        ~Logger()
        {

        }
    private:
        std::unique_ptr<LogStrategy> _fflush_strategy;
    };
    Logger logger;

    #define LOG(level) logger(level, __FILE__, __LINE__)
    #define Enable_Console_Log_Strategy() logger.EnableConsoleLogStrategy();
    #define Enable_File_Log_Strategy() logger.EnableFileLogStrategy();
}

#endif